Abstract
A method is presented for designing smooth blending between structural surfaces when only local alterations of the original surfaces are allowed. A simple kinematic analogy to the blending process is to represent the blending surface as the envelope of a sphere, possibly of variable radius, moving while in contact with the original surfaces. This scheme is then generalized to blending surfaces which can be represented by sweeping a (possibly variable) arc of circle. By design, this method guarantees continuity of the unit surface normal and of the normal radius of curvature along the common boundary with the blending surface, called the linkage curve.
